A pressure sensor including a housing provided with a flow channel to which a liquid, such as a drug solution, is guided, and a sensor element for detecting a pressure of liquid to be transmitted to a pressure-sensitive portion in contact with the liquid guided to the flow channel has been conventionally known (for example, see the Publication of Japanese Patent No. 4846140 (hereinafter referred to as “JP 4846140”)).
In the pressure sensor disclosed in JP 4846140, since the housing and the pressure-sensitive portion are formed of a material including, as a main component, a fluorine-contained resin having an excellent chemical resistance, static electricity is likely to be accumulated on the housing and the pressure-sensitive portion due to a friction with the liquid. Accordingly, the pressure sensor disclosed in JP 4846140 has a structure in which aluminum foil is attached to the surface of the sensor element that is in contact with the pressure-sensitive portion, thereby allowing the static electricity accumulated on the pressure-sensitive portion to be discharged to a shield line.